| Cover | Jun. 12, 2024 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 12, 2024 |
| Entity File Number | 001-40251 |
| Entity Registrant Name | Newbury Street Acquisition Corporation |
| Entity Central Index Key | 0001831978 |
| Entity Tax Identification Number | 85-3985188 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 121 High Street |
| Entity Address, Address Line Two | Floor 3 |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02110 |
| City Area Code | 617 |
| Local Phone Number | 893-3057 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Units, each consisting of one share of Common Stock and one-half of one redeemable warrant | |
| Title of 12(b) Security | Units, each consisting of one share of Common Stock and one-half of one redeemable warrant |
| Trading Symbol | NBSTU |
| Security Exchange Name | NASDAQ |
| Common Stock, par value $0.0001 per share | |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | NBST |
| Security Exchange Name | NASDAQ |
| Warrants, each exercisable for one share of Common Stock for $11.50 | |
| Title of 12(b) Security | Warrants, each exercisable for one share of Common Stock for $11.50 |
| Trading Symbol | NBSTW |
| Security Exchange Name | NASDAQ |
